This invention relates generally to rotary pneumatic motors and pneumatic tools incorporating the same, and more particularly to rotary pneumatic air motors and pneumatic tools having improved performance and bias capabilities.
Conventional rotary pneumatic tools, such as impact wrenches, comprise a housing and a pneumatic motor disposed in the housing. The pneumatic motor is powered by pressurized air received in the housing that drives rotation of a shaft supported by the housing. The shaft projects outward from the housing for engaging a fastener element, such as a nut or a bolt. The tools are typically provided with a control mechanism for switching the mode of operation of the tool between a forward operating mode in which the fastener element is tightened and a reverse operating mode in which the fastener element is loosened. Because many times fastener elements to be loosened are rusted, corroded, and/or damaged, it is often desirable to design the tool with a reverse bias in which the maximum torque of the tool occurs in the reverse direction.
The foregoing illustrates limitations known to exist in present pneumatic devices. Thus it is apparent that it would be advantageous to provide an alternative directed to overcoming one or more of the limitations set forth above. Accordingly, pneumatic motor improvements and pneumatic tools incorporating the same are provided including the features more fully disclosed hereinafter.